Comparative Evaluation of Physicochemical and Bioactive Properties of Adansonia digitata Seed Roasted Brew from Selected Zimbabwean Locations and Roasting Conditions

Abstract

The increasing demand for functional foods has stimulated interest in underutilized indigenous resources with potential nutritional and health benefits. This study comparatively evaluated the physicochemical and bioactive properties of A. digitata seed roasted brew prepared from selected Zimbabwean locations under different roasting conditions. Baobab seeds collected from three ecologically distinct regions of Zimbabwe, Manicaland, Masvingo, and Mashonaland East were roasted at 150 °C, 175 °C, and 200 °C, representing light, medium, and dark roasts, respectively. Brewed samples were evaluated for physicochemical attributes (pH, titratable acidity, moisture content, total soluble compounds, viscosity, crude fibre, and sugar concentration) and bioactive properties (total phenolics, flavonoids, antioxidant activity and caffeine content). Variation in the measured parameters was observed across the roasting temperatures and selected locations investigated. The 175 °C roasting condition produced comparatively favourable values for several measured physicochemical and bioactive characteristics. Masvingo samples exhibited the highest total phenolic content (4.39 ± 0.12 mg GAE/g), total flavonoid content (9.39 ± 0.26 mg RE/g), and DPPH radical scavenging activity (77.69 ± 3.60%), indicating potential for functional beverage production. In contrast, Manicaland samples showed higher moisture content and comparatively lower antioxidant constituents, while Mashonaland East samples retained higher crude fibre levels. Caffeine was not detected in the analysed samples under the analytical conditions employed. Overall, the findings demonstrate variation in the physicochemical and bioactive characteristics of A. digitata seed roasted brew across the selected locations and roasting conditions, while sensory responses varied across the geographical samples evaluated at 175 °C. The results provide preliminary evidence supporting further investigation of baobab seed as a potential raw material for development of alternative roasted beverages. Further studies using multiple independent biological lots from each location are recommended to establish the reproducibility and broader applicability of these observations